Diaz served four years in state prison for false imprisonment and possession of a controlled substance beginning in 2007. He also had been convicted of misdemeanor charges of molestation involving juveniles.

When the 46-year-old sex offender was released from custody, he was required to register on the Megan's Law website, which he did.

Based on Diaz’s criminal record he was required to give only his zip code.

The San Diego County SAFE Task Force tracks offenders. They told NBC 7 they were aware of Diaz, that he lived across the street from Oak Park Elementary School and that he was compliant prior to his arrest on Saturday.